Container Engine — Docker & Podman

Distro support

Two-family skill. The two engines are Docker (a root daemon, dockerd, managed by docker.service) and Podman (daemonless, rootless by default, shipped and preferred by the RHEL family). Both speak the OCI image format and share most CLI verbs, but they configure differently: Docker reads /etc/docker/daemon.json; Podman reads /etc/containers/*.conf (registries.conf, storage.conf, containers.conf). The body below uses Docker on Debian/Ubuntu; substitute per this matrix.